Sump pump discharge sizing
Sump pump discharge sizing
(OP)
Hello,
I'm looking for a little advice on if I should upsize the discharge on my home's sump pump. After upgrading the pump size it still can't keep up, but only by the smallest of margins during absurd amount of rainfall. I'm making other improvements to prevent water making it to the sump pit but was wondering if upsizing the discharge line, which is an easy fix, would help in the meantime. The current setup is as follows:
Pump:
Flotec ½ HP
0 head = 4680 GPH
5 head = 4380 GPH
10 head = 3840 GPH
15 head = 3300GPH
20 head = 2340 GPH
Discharge:
1 ½" PVC
10' vertical run
Single smooth 90 degree elbow
23' horizontal run
20' of 1 ½" corrugated discharge line
What is the maximum discharge of the current setup and would upsizing to 2' improve the output?
Any help you may provide would be most appreciated. Thank you.
I'm looking for a little advice on if I should upsize the discharge on my home's sump pump. After upgrading the pump size it still can't keep up, but only by the smallest of margins during absurd amount of rainfall. I'm making other improvements to prevent water making it to the sump pit but was wondering if upsizing the discharge line, which is an easy fix, would help in the meantime. The current setup is as follows:
Pump:
Flotec ½ HP
0 head = 4680 GPH
5 head = 4380 GPH
10 head = 3840 GPH
15 head = 3300GPH
20 head = 2340 GPH
Discharge:
1 ½" PVC
10' vertical run
Single smooth 90 degree elbow
23' horizontal run
20' of 1 ½" corrugated discharge line
What is the maximum discharge of the current setup and would upsizing to 2' improve the output?
Any help you may provide would be most appreciated. Thank you.





RE: Sump pump discharge sizing
What is really hurting you is the corrugated discharge line. Corrugated tubing has very bad hydraulic properties and much higher resistance to flow.
It is not clear from your post where the 20' of 1 ½" corrugated discharge line is installed. So it is difficult to estimate the flow increase.
In any case, I would replace the 20' of 1.5" corrugated discharge tubing with pipe.
RE: Sump pump discharge sizing
The solid PVC run includes the vertical to the basement ceiling and out to exterior wall, where it is connected to the 20' of 1 1/2" corrugated line on the exterior.
RE: Sump pump discharge sizing
RE: Sump pump discharge sizing
RE: Sump pump discharge sizing
You can look in a piping handbook to get the friction losses in your system now for various flows. Usually these losses will be in psi/100'ft. Of course 1psi=2.31 feet head.
Just look at the difference in losses between 1-1/2" pipe and any larger size you want to install and make sure the difference is going to be worth the changeout. I am too tired right now to go over how to convert the deltaPs into flow changes.
RE: Sump pump discharge sizing
I concede I'm starting with 10' of head (3840 gph max), however would replacing the 1 1/2" PVC with 2 1/2" reduce the the friction loss significantly? I imagine I'm close to a 20' of head loss with the current setup, if not more.
Not including the 20' of corrugated hose what would be the max output for my current setup? What would it be with 2 1/2" PVC?
How large of an effect would replacing the corrugated with PVC have?
Thank you for your help.
RE: Sump pump discharge sizing
From "BigInch's Extremely simple theory of everything."
RE: Sump pump discharge sizing
ht
Assuming the corrugated pipe is removed, use the calculator to estmate the pipe losses due to flow:
@3840 gph 1.5-Inch pipe headloss = 6.4 Ft
@3840 gph 2-Inch pipe headloss = 1.9 Ft
@3300 gph 1.5 -Inch pipe headloss = 4.9 Ft
So you are probably pumping approximately 3100-3200 gph (without the corrugated piece). If you replace with 2-Inch pipe, you can probably get 3400-3500 gph. If you go with 2.5-Inch pipe, you can probably get 3800 gph.
RE: Sump pump discharge sizing
I came across this site:
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Assuming a flow rate of 3600 gph would the head loss for the 20' of 1 1/2" corrugated section be ~8 feet?
RE: Sump pump discharge sizing
http:
I believe that you are using a factor of 120 which is for smooth wall plastic pipe and not appropriate for corrugated pipe.